Combustion and Flame Test

Result

Combustion and Flame Test - 21

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
1 / -0

One of the phenomenon which cannot be described as combustion is:

A
oxidation of coal in air

B
burning of magnesium in nitrogen

C
reaction of antimony in chlorine

D
lighting of an electric lamp

Solution

Lighting of an electric lamp cannot be described as combustion. During the lighting of an electric lamp, the electrical energy is converted into light energy. However, during combustion, chemical energy is converted into thermal energy.
Question 2
1 / -0

In photosynthesis in plants, $${H}_{2}O$$ and $${CO}_{2}$$ react in presence of light and chlorophyll to give carbohydrate and oxygen. When the carbohydrate is burnt in air, the gases produced are:

A
$${CO}_{2}+{H}_{2}$$

B
$${CO}_{2}+CO$$

C
$${CO}_{2}+{H}_{2}O$$

D
$${CO}_{2}+{O}_{2}$$

Solution

The carbohydrate is glucose. The combustion of glucose is as follows:

$$C_6H_{12}O_6 + 6O_2 \rightarrow 6 H_2O + 6CO_2 + heat $$

Combustion occurs when any organic material is reacted (burned) in the presence of oxygen to give off the products of carbon dioxide, water and energy. This is simply the process of metabolism.
Question 3
1 / -0

Which of the following diagrams shows a non-luminous flame?

A
I only

B
II only

C
I and II

D
II and IV

Solution

A blue colored flame which produces very little light is called non-luminous flame. In other words when a fuel undergoes complete combustion it is non luminous flame.
Question 4
1 / -0

When a burning candle is covered with a glass it extinguishes because:

A
supply of oxygen is cut off

B
supply of hydrogen is cut off

C
supply of nitrogen is cut off

D
supply of $$CO_2$$ is cut off

Solution

This happens because oxygen in the air inside the glass tumbler is utilized in burning the candle. All the oxygen gets converted into carbon dioxide. Carbon dioxide does not support burning and hence candles stop burning.
Question 5
1 / -0

There are holes below the chimney of an oil lamp:

A
to supply oxygen for burning the oil

B
to let the smoke escape

C
to increase the brightness of the lamp

D
None of these

Solution

Oxygen is a supporter of combustion. In its absence, the oil cannot burn. So, holes are provided at the bottom of the lamp to ensure a continuous supply of oxygen to allow the oil to burn.

Hence, option $$A$$ is correct.
Question 6
1 / -0

The characteristic(s) of a ideal fuel is(are):

A
it should release a large amount of energy

B
it should burn moderately in air

C
it should be easily transported

D
all of the above
Solution
Ideal fuel shows the following characteristics:
- It should be inexpensive,
- It should have a low ignition temperature
- It should be easily available,
- It should produce a large amount of heat,
- It can be easily transported.
- It has a high calorific value.
- It should burns easily in the air at a moderate rate.
Hence option D is correct.
Question 7
1 / -0

Which among the following has the highest calorific value?

A
Petrol

B
Cow dung cake

C
Coal

D
Wood

Solution

Here are the calorific values of the given fuels:

a) Petrol: 45000 kJ/kg
b) Cow dung cake: 6000-8000 kJ/kg
c) Coal: 25000-33000 kJ/kg
d) Wood: 17000-22000 kJ/kg

So, petrol has the highest calorific value among the given fuels.
Question 8
1 / -0

The flame of the candle has three zones. The outer zone is blue, the middle zone is yellow and the inner zone is black. Which is correct regarding this?

A
The outer zone is least hot

B
The middle zone is hottest

C
The inner zone is least hot

D
All the zones have same temperature

Solution

The hottest part of the flame is the outer zone with blue color which has the highest temperature due to complete combustion, the yellow part of the flame has a temperature less than the outer part.
While the innermost zone is black in color which has the least temperature. This black color is due to unburnt wax vapors. So as the distance of the flame from the centerline increases the temperature increases.

Hence, option $$C$$ is correct.
Question 9
1 / -0

Which among the following has the highest calorific value?

A
Hydrogen

B
Wood

C
Coal

D
Methane

Solution

The amount of heat energy produced on complete combustion of 1 kg of a fuel is called its calorific value. The calorific value of a fuel is expressed in a unit called $$kilojoule \ per\ kg (kJ/kg)$$.
Hydrogen has the highest calorific value of about $$150000 \ kJ/kg$$ whereas the calorific value of wood, coal, and petrol is less than $$50000\ kJ/kg$$
Question 10
1 / -0

Quality that is not suitable for a fuel is ________ .

A
high calorific value with ignition temperature that is well above the normal room temperature

B
low rate of evaporation at room temperature

C
carbon particles are expelled with smoke

D
low content of non-combustibles

Solution

Quality that is not suitable for fuel is carbon particles are expelled with smoke and cause air pollution.

User

Question Analysis

Correct -
Wrong -
Skipped -

My Perfomance

Score
-
out of -
Rank
-
out of -

Re-Attempt Weekly Quiz Competition

Combustion and Flame Test - 21

Result

Combustion and Flame Test - 21

Score

-

Rank

-

SHARING IS CARING

Question 1

oxidation of coal in air

burning of magnesium in nitrogen

reaction of antimony in chlorine

lighting of an electric lamp

Solution

Question 2

$${CO}_{2}+{H}_{2}$$

$${CO}_{2}+CO$$

$${CO}_{2}+{H}_{2}O$$

$${CO}_{2}+{O}_{2}$$

Solution

Question 3

I only

II only

I and II

II and IV

Solution

Question 4

supply of oxygen is cut off

supply of hydrogen is cut off

supply of nitrogen is cut off

supply of $$CO_2$$ is cut off

Solution

Question 5

to supply oxygen for burning the oil

to let the smoke escape

to increase the brightness of the lamp

None of these

Solution

Question 6

it should release a large amount of energy

it should burn moderately in air

it should be easily transported

all of the above

Solution

Question 7

Petrol

Cow dung cake

Coal

Wood

Solution

Question 8

The outer zone is least hot

The middle zone is hottest

The inner zone is least hot

All the zones have same temperature

Solution

Question 9

Hydrogen

Wood

Coal

Methane

Solution

Question 10

high calorific value with ignition temperature that is well above the normal room temperature

low rate of evaporation at room temperature

carbon particles are expelled with smoke

low content of non-combustibles

Solution

User

Question Analysis

My Perfomance

Score

-

Rank

-

Results Announcement on: coming Monday

Stay Tuned: We’ll update you on your result via email or SMS.